1. Technical Field
The present invention relates to a recording device which is typified by a fax machine, a printer, or the like, and particularly relates to a recording device in which the load of a driven roller can be switched for ejection unit provided downstream of recording unit.
2. Related Art
Inkjet printers in particular are described hereinbelow as examples of recording devices. A roller pair composed of a drive roller formed from rubber or another elastic material and a driven roller (a toothed roller) having teeth in the outer periphery is sometimes used as the paper ejection unit provided downstream of the recording unit in an inkjet printer. The reason a driven roller having teeth in the outer periphery is used is to prevent the ink from transferring because the roller comes in contact with the recording surface on which the ink is discharged.
Some inkjet printers are capable of performing edgeless recording in which recording is performed without leaving any white space on the four sides of the paper. In this type of inkjet printer, after the rear end of the paper has left the conveying roller upstream of the recording head, edgeless recording is performed on the rear end region including the rear end of the paper while the paper is fed by the ejection unit.
Particularly in cases in which the paper is cut into sheets of paper, when the rear end of the paper leaves the conveying roller upstream of the recording head, there are fewer roller pairs sandwiching the paper, the rear end of the paper rises upward readily, and there is a risk that the paper quality will suffer. Therefore, there are also cases in which two roller groups are provided in the paper conveying direction as the ejection unit, and the paper is sandwiched by these two roller groups, thereby preventing the rear end of the paper from rising upward during recording on the region at the rear end of the paper.
Furthermore, depending on the recording device, there are those which are configured so that the contact load (the load when the paper is nipped) of the driven roller (a toothed roller) on the drive roller can be varied, and are also configured so that the contact load is adjusted according to the ink discharge quantity, as shown in Japanese Laid-Open Patent Publication No. 2007-326707. According to this recording device, for example, the contact load can be reduced for a recording region having a large, ink discharge quantity, the contact load can be increased for a recording region having a small ink discharge quantity, and the risk of the driven roller (a toothed roller) leaving traces of contact on the recording surface can be reduced. Japanese Laid-Open Patent Publication No. 2005-169749 discloses a recording device which switches between a knurl roller and a runner roller depending on the type of paper.